Ultrastructural analyses of modular subunits in the mushroom bodies of the cockroach
Ultrastructural analyses of modular subunits in the mushroom bodies of the cockroach
复制标题
蟑螂蘑菇体中模块亚基的超微结构分析
DOI：
10.1093/oxfordjournals.jmicro.a023651
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Y. Tominaga
中科院分区：
文献类型：
--
作者：
M. Iwasaki;M. Mizunami;M. Nishikawa;T. Itoh;Y. Tominaga
蘑菇体是昆虫大脑的高级中心，涉及感觉联想、记忆和某些形式的运动控制。最近我们报道了蟑螂蘑菇体的输出区域存在 15 个重复模块亚基。每个模块化子单元均由浅色和深色板组成。为了阐明该单元结构的形态组织和功能，我们比较了亮板和暗板的超微结构。花梗由大量紧密堆积的凯尼恩细胞轴突 (KCA)、神经胶质突起和外在纤维组成。 KCA 中的外在纤维和突触小泡在花梗中的出现频率远低于在 α 和 β 叶中的出现频率。然而，花序梗还显示出浅色和深色的板片以及裂片。对花柄中横向切片 KCA 的超微结构定量分析表明，浅色板中 KCA 的平均直径比相邻深色板中的 KCA 平均直径大 5-18%，差异显着。这些结果表明，KCA 的直径是导致板坯密度变化的主要因素，至少在花梗中是这样。由于 KCA 直径不同而导致的传导速度差异可用于信号处理。
The mushroom body is a higher centre of the insect brain involved in sensory association, memory, and some forms of motor control. Recently we have reported that 15 repetitive modular subunits are present in the output regions of the mushroom body in the cockroach. Each modular subunit consists of light and dark slabs. Seeking to clarify morphological organization and function of this unit structure, we compared the ultrastructure of the light and the dark slabs. The pedunculus comprises a huge number of tightly packed Kenyon cell axons (KCAs), glial processes, and extrinsic fibres. The extrinsic fibres and synaptic vesicles in KCAs occur much less frequently in the pedunculus than in α and β lobes. Nevertheless, the pedunculus also reveals light and dark slabs as well as lobes. Ultrastructural quantitative analyses of transversely sectioned KCAs in the pedunculus show that average diameters of KCAs in the light slabs are 5–18% larger than those in the adjacent dark slabs, which are significantly different. These results suggest that the diameter of KCAs is the major factor contributing to the varied density of slabs, at least in the pedunculus. Difference in conduction velocities due to varied diameters of KCAs may be utilized for signal processing.